What Is A Stroke?

A stroke is a disease that affects the arteries leading to and within the brain. It is the No. 3 cause of death in the United States, behind diseases of the heart and cancer. A stroke occurs when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a clot or bursts. When that happens, part of the brain cannot get the blood (and oxygen) it needs, so it starts to die.

• Warning Signs of Stroke
• Types of Strokes
• Diagnosing Stroke

• Acute and Preventive Stroke Treatments
• How Stroke Affects the Brain
• Physical Effects of Stroke

Warning Signs of Stroke

Sometimes symptoms of a stroke are difficult to identify. Unfortunately, the lack of awareness spells disaster. The stroke victim may suffer severe brain damage when people nearby fail to recognize the symptoms of a stroke. Now doctors say a bystander can recognize a stroke by asking three simple questions:

S - Ask the individual to SMILE

T - Ask the person to SPEAK A SIMPLE SENTENCE (Coherently) (eg "It is sunny out today")

R - Ask the person to RAISE BOTH ARMS

A stroke is a medical emergency. Know these warning signs of stroke and teach them to others. Every second counts:

• Sudden numbness or weakness of the face, arm or leg, especially on one side of the body
• Sudden confusion, trouble speaking or understanding
• Sudden trouble seeing in one or both eyes
• Sudden trouble walking, dizziness, loss of balance or coordination
• Sudden, severe headache with no known cause

If you or someone with you has one or more of these signs, don't delay! Immediately call 9-1-1 or the emergency medical services (EMS) number so an ambulance (ideally with advanced life support) can be sent for you. Also, check the time so you'll know when the first symptoms appeared.

It's very important to take immediate action. If given within three hours of the start of symptoms, a clot-busting drug called tissue plasminogen activator (tPA) can reduce long-term disability for the most common type of stroke. tPA is the only FDA-approved medication for the treatment of stroke within three hours of stroke symptom onset.

A TIA or transient ischemic attack is a "warning stroke" or "mini-stroke" that produces stroke-like symptoms but no lasting damage. Recognizing and treating TIAs can reduce your risk of a major stroke. The usual TIA symptoms are the same as those of stroke, only temporary. The short duration of these symptoms and lack of permanent brain injury is the main difference between TIA and stroke.

Types of Strokes

If we consider an isolated blood vessel, blood flow to the brain tissue can be hampered in two ways:

1. Ischemic

Ischemic stroke accounts for about 87 percent of all cases. Ischemic strokes occur as a result of an obstruction within a blood vessel supplying blood to the brain. The underlying condition for this type of obstruction is the development of fatty deposits lining the vessel walls. This condition is called atherosclerosis. These fatty deposits can cause two types of obstruction:

Cerebral thrombosis refers to a thrombus (blood clot) that develops at the clogged part of the vessel.

Cerebral embolism refers generally to a blood clot that forms at another location in the circulatory system, usually the heart and large arteries of the upper chest and neck. A portion of the blood clot breaks loose, enters the bloodstream and travels through the brain's blood vessels until it reaches vessels too small to let it pass. A second important cause of embolism is an irregular heartbeat, known as atrial fibrillation. It creates conditions where clots can form in the heart, dislodge and travel to the brain.

2. Hemorrhagic

Hemorrhagic stroke accounts for about 13 percent of stroke cases. It results from a weakened vessel that ruptures and bleeds into the surrounding brain. The blood accumulates and compresses the surrounding brain tissue. The two types of hemorrhagic strokes are intracerebral hemorrhage or subarachnoid hemorrhage.

Hemorrhagic stroke occurs when a weakened blood vessel ruptures. Two types of weakened blood vessels usually cause hemorrhagic stroke: aneurysms and arteriovenous malformations (AVMs).

An aneurysm is a ballooning of a weakened region of a blood vessel. If left untreated, the aneurysm continues to weaken until it ruptures and bleeds into the brain. Learn more about cerebral aneurysm.

An arteriovenous malformation (AVM) is a cluster of abnormally formed blood vessels. Any one of these vessels can rupture, also causing bleeding into the brain

Diagnosing Stroke

When someone has shown symptoms of a stroke or a TIA (transient ischemic attack), a doctor will gather information and make a diagnosis. He or she will review the events that have occurred and will:

• get a medical history
• do a physical and neurological examination
• have certain laboratory (blood) tests done
• get a CT or MRI scan of the patient
• study the results of other diagnostic tests that might be needed

Diagnostic Tests

Diagnostic tests examine how the brain looks, works and gets its blood supply. They can outline the injured brain area. Most of them are safe and painless. Diagnostic tests fall into three categories.

• Imaging tests give a picture of the brain similar to X-rays
• Electrical tests record the electrical impulses of the brain
• Blood flow tests show any problem that may cause changes in blood flow to brain

Common Imaging Tests

CT scan (computed tomography) or CAT scan is a key imaging test. It uses radiation to create a picture of the brain. It's usually one of the first tests given to patients suspected of stroke. CT test results give valuable information about the cause of stroke and the location and extent of brain injury.

MRI (magnetic resonance imaging) uses a large magnetic field to produce an image of the brain. Like the CT scan, it shows the location and extent of brain injury. The image produced by MRI is sharper and more detailed than a CT scan so it's often used to diagnose small, deep injuries.

Electrical Activity Test

Two basic tests, EEG and Evoked Response, show the brain's electrical activity.

• In an EEG (electroencephalogram), small metal discs (electrodes) are placed on a person's scalp to pick up electrical impulses. These electrical signals are printed out as brain waves.


• An Evoked Response test measures how the brain handles different sensory information. Electrodes record electrical impulses related to hearing, body sensation or vision.

Blood Flow Test

Several blood flow tests exist; most use ultrasound technology. A probe is placed over the suspect artery - especially arteries in the neck (carotid) or at the base of the skull ( vertebral) - and the amount of blood flow is determined.

Examples of blood flow tests are B-mode imaging, Doppler testing and duplex scanning. These tests give detailed information about the condition of arteries.

Another blood flow test is a medical procedure called angiography (arteriography or arteriogram). This test is like a cardiac catheterization, only the catheter is placed in the arteries of the brain rather than in the arteries of the heart. In this test, a special dye is injected into the blood vessels and an X-ray is taken.

Angiography gives a picture of the blood flow through the vessels. This allows the size and location of blockages to be evaluated. This test can be especially valuable in diagnosing aneurysms and malformed blood vessels and providing information before surgery.

Acute and Preventive Stroke Treatments

Because their mechanisms are different, the treatments for the types of stroke are different:

• Ischemic stroke is treated by removing obstruction and restoring blood flow to the brain.


• In hemorrhagic stroke, doctors introduce an obstruction to prevent rupture and bleeding of aneurysms and arteriovenous malformations.

Ischemic Stroke

• Clot busters, e.g., tPA
  The most promising treatment for ischemic stroke is the FDA-approved clot-busting drug tPA (tissue plasminogen activator), which must be administered within a three-hour window from the onset of symptoms to work best. Administering tPA or other clot-dissolving agents is complex and is done through an intravenous (IV) line in the arm by hospital personnel. If given promptly, tPA can significantly reduce the effects of stroke and reduce permanent disability. Generally, only 3 to 5 percent of those who suffer a stroke reach the hospital in time to be considered for this treatment.

• Anticoagulants/Antiplatelets
  Antiplatelet agents such as aspirin and anticoagulants such as warfarin interfere with the blood's ability to clot and can play an important role in preventing stroke.


• Carotid Endarterectomy
  Carotid endarterectomy is a procedure in which blood vessel blockage is surgically removed from the carotid artery.


• Angioplasty/Stents
  Doctors sometimes use balloon angioplasty and implantable steel screens called stents to treat cardiovascular disease and reduce fatty buildup clogging a vessel.

Hemorrhagic Stroke (Subarachnoid hemorrhage or AVM)

• Surgical Intervention
  For hemorrhagic stroke (specifically for a subarachnoid hemorrhage), surgical treatment is often recommended to either place a metal clip at the base, called the neck, of the aneurysm or to remove the abnormal vessels comprising an arteriovenous malformation (AVM).


• Endovascular Procedures, e.g., "coils"
  Endovascular procedures are less invasive and involve the use of a catheter introduced through a major artery in the leg or arm, guided to the aneurysm or AVM where it deposits a mechanical agent, such as a coil, to prevent rupture.

How Stroke Affects the Brain

The brain is an extremely complex organ that controls various body functions. If a stroke occurs and blood flow can't reach the region that controls a particular body function, that part of the body won't work as it should.

If the stroke occurs toward the back of the brain, for instance, it's likely that some disability involving vision will result. The effects of a stroke depend primarily on the location of the obstruction and the extent of brain tissue affected.

Right Brain

The effects of a stroke depend on several factors, including the location of the obstruction and how much brain tissue is affected. However, because one side of the brain controls the opposite side of the body, a stroke affecting one side will result in neurological complications on the side of the body it affects. For example, if the stroke occurs in the brain's right side, the left side of the body (and the right side of the face) will be affected, which could produce any or all of the following:

• Paralysis on the left side of the body
• Vision problems
• Quick, inquisitive behavioral style
• Memory loss

Left Brain

If the stroke occurs in the left side of the brain, the right side of the body will be affected, producing some or all of the following:

• Paralysis on the right side of the body
• Speech/language problems
• Slow, cautious behavioral style
• Memory loss

Physical Effects of Stroke

Spasticity

Spasticity is like a "wicked charley horse." Brain injury from stroke sometimes causes muscles to involuntarily contract (shorten or flex) when you try to move your limb. This creates stiffness and tightness.

When a muscle can't complete its full range of motion, the tendons and soft tissue surrounding it can become tight. This makes stretching the muscle much more difficult. If left untreated, the muscle can freeze permanently into an abnormal and often painful position.

Spasticity in the arm can cause a tight fist, bent elbow and arm pressed against the chest. This can seriously interfere with a stroke survivor's ability to perform daily activities such as dressing. Spasticity in the leg may cause a stiff knee, pointed foot and curling toes.

Balance

About 40 percent of stroke survivors have serious falls within a year of their stroke. In a study published in Stroke: Journal of the American Heart Association, women stroke survivors who reported difficulty maintaining their balance while dressing were seven times more likely to fall than women who didn't report balance problems.

In addition, overall balance problems, dizziness or a "spinning" sensation as the result of stroke were associated with a five-fold increase in risk of falls.

People with balance problems often benefit from physical therapy. Your first step is to get a therapy prescription from your physician.

Experts at the Long Beach Memorial Medical Center Balance and Vestibular Center give these suggestions for preventing falls at home:

• Use nightlights in bedrooms, bathrooms and hallways
• Make sure light switches are easily accessible
• Use bathmats with suction cups and non-adhesive strips in the tub
• Sit on a bench or stool in the shower and use a hand-held showerhead
• Don't walk around in stocking feet. Wear shoes or slippers that fit snugly
• Remove throw rugs and secure area rugs with double-sided tape
• Use a sturdy step stool with a handrail when reaching items up high
• Store frequently used items at waist level
• Review medications with your doctor as some may cause dizziness and imbalance
• If you feel lightheaded when first sitting or standing up, sit down and stay seated until your head clears, then stand up slowly
• Ask for help. If needed, a caregiver or family member should be ready, willing and able to help out
• Slow down and take all the time you need when walking. There is no need to hurry, and it may be safer to go more slowly

Claw Toe

Claw toe, and a similar condition called "hammertoe," are caused by an imbalance of muscles in the feet and toes. Brain injury during a stroke leaves survivors prone to neuromuscular imbalances. With claw toe, muscles in the foot over-contract due to a neurological abnormality.

Claw toe and hammertoe are very similar conditions, differing in the muscles affected — flexor digitorum brevis and flexor digitorum longus, respectively. For this reason, the terms "claw toe" and "hammertoe" are often used interchangeably.

Claw toe is classified in two ways - "flexible" or "rigid" - based on the severity and progression of the condition.

• Because toe muscles are typically not very strong, the contracting muscle overpowers the muscles in the toe.


• This tightens the tendons, causing the joints of the smaller toes to buckle or curl in an unnatural way.


• Claw toe most often strikes the stroke-side foot.


• Painful blisters may develop on the affected toes where their tips dig into the shoe.


• Added pressure from the imbalance may also cause calluses or corns to form on the ball of the foot.


• Claw toe also affects patients with joint diseases such as rheumatoid arthritis, cerebral palsy, nerve damage due to poor circulation, as with diabetes, and those confined to bed for a long time.

Flexible Claw Toe

"Flexible claw toe" describes the earlier stages in which, as the name suggests, the toes are still flexible at the joint. The American Academy of Orthopaedic Surgeons (AAOS), in conjunction with the American Orthopaedic Foot and Ankle Society, offers these suggestions for helping to correct the imbalance of flexible claw toe:

• Follow your doctor's instructions, use a splint or athletic tape to reposition toes.
• Avoid shoes with heels over two inches.
• Wear soft shoes with plenty of room for the toes.
• Workout by using them to pick up small objects such as marbles or a crumpled towel.

Rigid Claw Toe

"Rigid claw toe" designates the later stages in which the toes are fixed in this unnatural position. As the tendons tighten and the deformity becomes fixed, fewer options are available. Non-surgical treatments are confined more to pain-management than to correcting the condition. To minimize discomfort for rigid claw toe, the AAOS recommends trying specialized shoes "that have an extra 3/8" depth in the toe box" or asking a "shoe repair shop to stretch a small pocket in the toe box to accommodate [the toes]."

Katherine Ware, a stroke survivor, recommends a different option: surgery. "I'd be on a cane if it weren't for the surgery," she said. The procedure involved cutting the tightened tendons. Other possible procedures include lengthening or repositioning tendons, or shortening the bone of the toe. Inserting a steel pin into the toe often corrects the problem.

As with all surgeries, infection is a risk, and swelling and pain are common in the following weeks. Ware says her surgery was "easy" with a "quick recovery." Although typically no tests are needed to identify claw toe, an X-ray will most likely be required if surgery is considered.

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